RESPIRATORY SYSTEM (RESPIRATION):
The normal respiratory rate of bears is 15 - 30 breaths per minute
(the higher rates have been recorded in hot weather); it is slower
during hibernation. The normal respiratory rate of bears is 15 - 30 breaths per minute
(the higher rates have been recorded in hot weather); it is slower
during hibernation. Much faster respiration can be seen in bears resting
in hot weather, e.g. 130 - 140 in cubs in summer.

CIRCULATORY SYSTEM (PULSE/HEART RATE): The normal heart rate of bears is 60 - 90 beats per minute (the
higher rates are found in cubs).

HAEMATOLOGY / BIOCHEMISTRY:
Values are similar to those of the domestic dog.

GASTROINTESTINAL SYSTEM (FAECES AND GUT MOTILITY):
Faeces (scats) are roughly cylindrical, sometimes coiled, usually dark brown,
and may contain visible seeds, grasses, insect parts, animal hair, nut
shells or root fibres; they may be black and liquid if bears are
feeding on berries. Food passage time is short.

URINARY SYSTEM (URINE): Urine specific gravity has
been measured as 1.025.

The American black bear's eyesight is poorer than that of humans,
but they do have colour
vision and at close range they have detailed vision and feed partially
by sight. Distance vision may not be sufficient to allow black bears
to stalk distant prey.

The sense of smell is excellent; they may smell carrion at a
distance of more than a mile (1.6 km). Scent is the main method used
by a female bear to recognise her offspring.

These bears have quite good hearing.

There are a variety of vocalisations, including a startled
"woof", contented purrs of cubs, shrill howls or squalls of
uncomfortable or frightened cubs and an "uh-uh" grunt by
females calling her cubs to her.

In captive bears in Virginia, USA, mean rectal temperature was 38.0
°C in autumn (fall) and 36.8 °C in winter during hibernation (108
measurements, from six bears). (J1.25.w6)

Body temperatures in hibernating bears [species not specified] have
been measured as 31 °C, 33 °C and 37.9 °C. (P72.2.w1)

Body temperatures in hibernating bears have been measured as 31.2-36
°C. (J345.10.w2)

During hibernation, metabolism averages 68% of predicted basal
metabolic rate and may reach as low as 33% of basal metabolisms. (J345.10.w2)

For four bears held at an experimental station in northern Michigan,
July body temperatures under anaesthesia averaged 98.6 °C, but in
February two bears had body temperatures averaging 95.3 °C. (J332.42.w2)

Source Information

SUMMARY: The normal respiratory rate of bears is 15 - 30 breaths per minute
(the higher rates have been recorded in hot weather); it is slower
during hibernation. Much faster respiration can be seen in bears resting
in hot weather, e.g. 130 - 140 in cubs in summer.

Normal respiration:

The normal respiratory rate of bears is 15 - 30 breaths per minute
(the higher rates have been recorded in hot weather). (B64.26.w5)

Source Information

SUMMARY: The normal heart rate of bears is 60 - 90 beats per minute (the
higher rates are found in cubs).

The normal heart rate of bears is 60 - 90 beats per minute (the
higher rates are found in cubs). (B64.26.w5)

In summer, the sleeping heart rate is usually above 40 beats per
minute. During winter hibernation, this declines gradually over
several weeks to reach 8-10 bpm. (P72.2.w1)

Four bears under pentobarbital sodium anaesthesia (following initial
immobilisation with succinyl choline) had pulse rates of 118 0 176 bpm
(mean 138 bpm), in July. Under the same regime in February, two had
pulse rates of 144 and 96. (J332.42.w2)

On ECG, the pattern of hibernating bears shows a short Q-T segment.
(P72.2.w1)

Source Information

SUMMARY:

Faeces (scats) are roughly cylindrical, sometimes coiled, usually dark brown,
and may contain visible seeds, grasses, insect parts, animal hair, nut
shells or root fibres; they may be black and liquid if bears are
feeding on berries. Food passage time is short.

When bears have been feeding heavily on berries, faeces may be
black and liquid. (B180)

Gastro-intestinal system:

Food passage times are short. Food is ground in the muscular
pylorus, and the stomach is highly acid (pH less than 3.5), assisting
in digestion of protein and sugars, as well as breakdown of
hemicellulose. The GIT appears adapted to digestion of fruit, nuts,
insects and succulent vegetation, not for mature, non-succulent
vegetation. (D248.w9)

Source Information

Source Information

SUMMARY:

The American black bear's eyesight is poorer than that of humans,
but they do have colour
vision and at close range they have detailed vision and feed partially
by sight. Distance vision may not be sufficient to allow black bears
to stalk distant prey.

The sense of smell is excellent; they may smell carrion at a
distance of more than a mile (1.6 km). Scent is the main method used
by a female bear to recognise her offspring.

These bears have quite good hearing.

There are a variety of vocalisations, including a startled
"woof", contented purrs of cubs, shrill howls or squalls of
uncomfortable or frightened cubs and an "uh-uh" grunt by
females calling her cubs to her.

Young cubs make a contented purr and squall if they are frightened or
uncomfortable. (B406.35.w35)

Females grunt "uh-uh" to bring her cubs to her, for example
calling them out of a tree they climbed for safety. (B406.35.w35)

"Small cubs squall when hungry, uncomfortable, or badly frightened
and voice a "purr" when comfortable or seeking comfort. This
sound resembles a rapid series of grunts rather than the throaty rumble of
cats." Older cubs use a "pleading bawl" to their
mother and this has been heard once as a call between two yearlings.
Females make a "huffing call"to cubs, and a
subdued "pump pump pump" call was heard repeatedly from a
female to her trapped cub. (D274)

A loud "huff" is made concurrently with a sudden protective
lunge and swat which may be made towards other bears or to humans. A
variable growl may be made before this action by some bears. "The
vocalisation leading into the physical action appears as threat under
circumstances wherein the threatener is fearful." Huffing is also
vocalised prior to charging. (D274)